I can’t answer your questions on the inactive mode since we’re not using at present (using expanded because we still have solar gain) but I can answer you can’t set WC coefficient dynamically but I can’t see why you would need to .

The app is very much worth getting you can scroll through days, consumption per hour, COP, room temp, outside temp and download full data set for a separate analysis from it. We been very pleased with daily COP of 6 usually and although early on Friday ~9am when it was recovering from set back and OAT was 2C the COP for the day was 3 by the end of the day’s temp profile the daily COP was 5. So it will definitely give you the information you need to optimise. 
But it’s a pig to install correctly we needed Vaillant support (and we’re technically minded).

@judith Sorted out the first issue with folk on the Vaillant fb page, it was a misunderstanding on my part.

Re the app - how do you find the data on cop etc stacks up against the data on the sensocomfort? Our hp is currently running at very low flow temps, around 24c, yet the scop recording is dropping from 4.25 to 3.8. The install is good, so I'm a bit concerned theres something going on in the background I need to adjust. One reason for getting the app would be to confirm that these numbers are correct.

The way I read the sensocomfort manual is the flow temperature on the curve only apply at a target indoor temp of 20. If you adjust this up or down the curve 'shifts about 5C for every 1C difference in the desires indoor tem.'. So in the day at 20C might be low 40C flow at an outside of 0C and with a 18C setback might be 30C flow at 0C outside.

I found https://energy-stats.uk/vaillant-arotherm-weather-curve-information/ which seems to back up the way I understand the manual.

Now I don't have a heat pump so this is what I understand with my system boiler & the sensocomfort controls. I'm pretty sure the behaviour is the same irrespective of heat source.

@gunboatdiplomat I found this useful for quickly working out diff flow rates.

https://heatcurve.psimonkey.org.uk/

The app and sensocomfort align for instantaneous readings but the app gives you the pattern over time and allows you to see heating and dhw independently. You might have the dhw set to keep refreshing the cylinder temperature for example and hence see cop variations which don’t make sense. We’re on timed for dhw.

I've not seen any difference in values between the two. You’ll need the sensocomfort to change the settings the app doesn’t do that much.

Posted by: @jwilliams89

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@gunboatdiplomat I found this useful for quickly working out diff flow rates.

 

https://heatcurve.psimonkey.org.uk/

This is great! Where did you find it?

@ectoplasmosis Someone sent it to me on a post on FB. although interestingly the values are slightly different to those on the page on energy stats. Still a nice quick tool.

@jwilliams89 The reason for asking is that the tables on the Energy Stats website are incorrect, and in a way so is the Vaillant manual.

The actual heat curve equation is:

T_Flow = a * (HC * (T_set - T_out))^b + T_set

a = 2.55
b = 0.78

@ectoplasmosis So are you saying the page I posted is more correct?

@jwilliams89 Yes, it is accurate. You can verify it by modifying your desired temperature and checking the new target flow temp on the controller.

@ectoplasmosis I did wonder. I was noticing this was more similar to the readings I was actually seeing.